This new elevator packs two cars into one shaft — and they don't crash into each other

Elevator design hasn't changed much in the last century. There's
generally just one cabin in one shaft that moves up and
down.

Now engineers at ThyssenKrupp have
developed an elevator system called the Twin that fits two
cabins into one hoistway.

More people are moving to cities, so we
need smarter elevators, the company's North America
CEO, Patrick Bass, tells Tech Insider.

The German company will put North America's first
Twin elevators in a Georgia Tech building in Atlanta by
2018.

More than 200 buildings worldwide already have the Twin.

The elevator system features two cabins: one that
only travels between the lobby and lower floors and another
that only travels among the top floors.

To start, passengers choose their floor on a touchscreen panel
outside the elevator. The software pairs people going
to the same sections of the building so they don't have to
stop at unnecessary floors.

The top cabin can travel up to 13 mph, while the bottom one moves
at 9 mph. For comparison, the elevator in New
York's Empire State Building travels at
around 22 mph. China's Shanghai
Tower — due to be completed by 2018 — will
have the fastest elevator in the world at
around 46 mph.

While the Twin elevator moves slowly compared to these elevators,
it could be more efficient. For example, if you're on
the twentieth floor, you could be waiting a while
for a normal elevator to travel up one shaft from the lobby,
especially if it makes frequent stops along the way.

But with the Twin, you'd likely just wait a few seconds for the
upper cabin to reach you.

To keep the Twin cabins from crashing into each other,
the elevator's software monitors the space between cabins. If
they get too close, they automatically slow down to a stop or use
the more abrupt emergency brake if necessary.

The Twin elevator system can also allow for 40% more
passengers than a traditional elevator, the company says.
It's a different model than ThyssenKrupp's
previous Multi elevator system, which uses magnetic
levitation to travel up, down, and sideways without cables.

As Wired's Aarian Marshall
notes, the Twin design is pretty genius, especially for
workers who need to constantly move between floors. Hospital
doctors and nurses, for example, would likely benefit from an
elevator that could quickly and efficiently move them from
patient suites to offices to surgical rooms.